In a recent trial, a recombinant zoster vaccine induced robust antibody responses in people with HIV (PLWH) regardless of their CD4 count, with nearly all participants achieving humoral vaccine response after two doses, reports Medscape. However, cell-mediated immunity was weaker in PLWH than in those without HIV.
The researchers conducted a non-randomised clinical trial in South Korea (June 2023 to November 2024) to assess the immunogenicity and safety of recombinant zoster vaccine in PLWH across low and high CD4 counts and in participants without HIV.
They included 60 virologically suppressed PLWH on antiretroviral therapy and 10 participants without HIV; all participants were men, with a median age ranging from 52.0 to 58.5 years. PLWH were classified into low CD4 (< 300 cells/µL; n = 30) and high CD4 (≥ 300 cells/µL; n = 30) groups.
All participants received two 0.5-mL intramuscular doses of recombinant zoster vaccine at weeks zero and eight.
The primary outcome was the humoral vaccine response rate: at least a fourfold rise in anti-glycoprotein E antibody titres from baseline, measured four weeks after the second dose in participants who were initially seropositive.
Secondary outcomes included the cell-mediated vaccine response rate – at least a twofold rise in anti-glycoprotein E-specific CD4²⁺ T cells from baseline, also measured four weeks after the second dose – and reactogenicity, assessed on days three and seven after vaccination.
At one month after the second dose, the humoral vaccine response rate was 100% in all groups, with no between-group differences with respect to the fold increase in anti-glycoprotein E titres from baseline.
The cell-mediated vaccine response rate at one month after the second dose differed significantly across the groups: 33.3% among PLWH in the low CD4 group, 50.0% among PLWH in the high CD4 group, and 80.0% among participants without HIV (P = .041).
The most common adverse event was pain at the injection site within seven days of vaccination; no adverse events of grade 3 or higher were reported.
During the one-month follow-up after the second dose, no unsolicited serious adverse events or cases of herpes zoster were reported in any group.
The findings support the current guidelines recommending administration of RZV (recombinant zoster vaccine) to PLWH, regardless of the CD4 count,” the authors wrote.
The study was led by Min-Kyung Kim, National Medical Centre, and Hyeon Jae Jo, Seoul National University College of Medicine, both in Seoul, South Korea, and published online in the International Journal of Infectious Diseases.
Study details
Impact of CD4 T cell counts on the immunogenicity and safety of the recombinant zoster vaccine in people living with HIV
Min-Kyung Kim, Hyeon Jae Jo, Chan Mi Lee et al.
Published in International Journal of Infectious Diseases on 8 September 2026
Abstract
Objectives
People living with HIV (PLWH) are at increased risk for herpes zoster. This study aimed to evaluate and compare the immunogenicity and safety of the recombinant zoster vaccine (RZV) in PLWH across low and high CD4 counts, and in participants living without HIV (PLWoH).
Methods
In this non-randomised clinical trial, virologically suppressed PLWH receiving antiretroviral therapy and PLWoH received two doses of RZV. PLWH were stratified into low (<300 cells/μL) and high (≥300 cells/μL) CD4 groups. Anti-glycoprotein E (gE) antibody titres and gE-specific cell-mediated immunogenicity (CMI) were measured at baseline, 8 week’s post-dose one, and 4 weeks post-dose two. Vaccine response rates (VRRs), defined as a ≥4-fold antibody or ≥2-fold CMI increase, and reactogenicity were assessed.
Results
Sixty PLWH (30 low CD4, 30 high CD4) and 10 PLWoH (all male) were analysed. Anti-gE titres increased significantly after each dose with no between-group differences. All groups achieved 100% humoral VRR after dose two, whereas CMI VRR differed significantly (33.3% low CD4, 50.0% high CD4, 80.0% PLWoH; P=0.041). Reactogenicity profiles were comparable.
Conclusion
RZV elicited robust humoral immunity in PLWH, regardless of the CD4 count; however, CMI was lower in PLWH than in HIV-negative individuals.
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